Bicycle-crank attachment



(No Model.)

, A. T. BASCOM.

, BICYCLE CRANK ATTACHMENT.

Patented Apr. 14, 1896.

AUSTIN T. BASOOM, OF SIDNEY, OHIO.

BICYCLE-CRANK ATTACHMENT.

SPECIFICATION forming part of Letters Patent No. 558,463, dated April 14, 1896.

Application filed October 17, 1895. Serial No- 565,966. (No model.)

To all whom it may concern.-

Be it known that I, AUSTIN T. BAscoM, a citizen of the 'United States, residing at Sidney, in the county of Shelby and State of Ohio, have invented certain new and useful Improvements in Bicycle Crank Attachments, of which the following-is a specification, reference being had therein to the accompanying drawings.

My invention relates to improved means for attaching the pedal-pin to the pedal-crank of a bicycle; and it has for its object the production of means whereby the pedal-pin may be attached to the pedal-crank in such manner that the leverage of the former may be increased or diminished by the rider while the bicycle is in or out of motion.

The invention consists in certain details of construction and combination of parts, which will first be described in connection with the accompanying drawings, and then pointed out in the claims.

Figure 1 of the drawings is a front elevation of a pedal-crank, illustrating the application of my invention, the pedal-pin being shown in the position of greatest leverage. Fig. 2 is a side elevation of the same. Fig. 3 is a view in elevation, partly in section, of the invention, showing the pedal-pin in the position of least leverage. Fig. 4 is a perspective view of the various parts, shown separately.

Referring to the drawings, A is a pedalcrank, provided at its free end with an enlarged head 1, on the outer side of which is secured, or preferably formed integral therewith, a disk B, which is preferably of less diameter than the head 1. A small boltopening 2 extends centrally through the disk and head.

O represents a yoke, of a shape substantially as shown, its inner end being of a size and shape to conform to the head 1 when in place thereon, and its outer or free end being adapted to receive the pedal-pin D, on which the pedal E is mounted. The inner end of this yoke is recessed on each side, as at 3 and 4., respectively, these recesses being of slightly greater diameter and depth than the diameter and thickness of disk B. An interiorlyscrew threaded opening 5 joins these re cesscs, this opening 5 being of less diameter than said recesses, thus leaving a shoulder (3 at its inner end and a shoulder 7 at its outer end, for a purpose hereinafter described.

F represents a coupling-bolt, the head 8 of which is exactly similar in size and construction to disk B. The part 9 of this bolt, next the head, is screw-threaded, as shown, and is one-half thread longer than the length of opening 5, the threads on this part 9 being adapted to conform to the threads in opening 5. The remaining portion of the bolt F is reduced in size, as at 10, and screw-threaded, this portion being adapted to enter the boltopening 2 and be engaged by a nut 11, as shown in Fig. 3.

In assembling the parts the coupling-bolt is passed through opening 5 until the threads on part 9 engage the threads in that opening, when it is screwed in until the head 8 rests in the recess 4, which is of a size to just receive it. The portion 10 of the bolt is now passed through the opening 2 until the end of portion 9 engages the face of disk B, when the nut 11 is screwed on the outer end of part 10, and the parts are assembled.

The operation of my invention is as follows Supposing it is desired to put the pedal-pin in the position of greatest leverage, which position is shown in Fig. 1. Now by simply turning the yoke forward (which operation, owing to the fact that the screw-threaded part 9 of the coupling-bolt is one-half thread longer than the interiorly-screw-threaded opening 5 in the yoke with which the part 9 engages, causes the yoke to move slightly inward) the shoulder 6 is caused to contact with the disk B until, when the parts assume the position shown in Fig; 1, the shoulder 6 and disk B are in such close contact that further forward movement of the yoke is impossible. Then when it is desired to put the pedal-pin in the position of least leverage, which position is shown in Fig. 3, by simply turning the yoke in the rearward direction the shoulder 7 is caused to contact with the head 8 of the bolt F until, when the parts are in the position shown in Fig. 3, further rearward movement of the yoke is impossible. As it is only necessary to turn the yoke in order to alter the leverage from the maximum to the minimum, or vice versa, it is evident that this operation can be readily and easily accomplished by the foot of the rider while the bicycle is in motion. From the fact that the recesses 3 and 4 are of a size to only just receivewhe disk B and head 8, respectively, it will be seen that these parts are practically clustproof.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a bicycle, the combination, with a pedal-crank having a disk on its free end, of a yoke recessed to receive said disk and having a central interiorly-screw-threaded opening, a pedal-pin secured to the yoke, and a coupling-bolt having a screw-threaded portion adapted to engage with the opening in the yoke, said bolt being adapted to secure the yoke to the crank in such manner as to permit a limited revolution of the yoke;

2. In a bicycle, the combination, with a pedal'crank having a disk on its free end, of a yoke recessed on both sides and having an interiorly-screw-threaded opening connecting said recesses, a pedahpin secured to the yoke, and a coupling-bolt having a head adapted to enter one of the recesses in the yoke, the other recess being adapted to receive said disk, the coupling-bolt having a screw-threaded portion adapted to enter the opening in the yoke and a reduced screwthreaded shank for securing the bolt to the crank, whereby the forward movement of the yoke causes the recess on one side to engage the head of the bolt and rearward movement of the yoke causes the recess on the other side to engage the disk on the crank, as and for the purposes stated.

In testimony whereof I afiix my signature in presence of two witnesses.

AUSTIN T. BASCOM. Witnesses:

LOUIS PFOADT, ROBERT E. VANI-IORN. 

